Steel sheet having a nickel composite film and a method for manufacturing the same

ABSTRACT

A steel sheet is cleaned and coated with a particular treating solution. This solution is obtained by adding Mo, W, Cu or K ion to Ni ion as the respective aqueous solutions. The film formed thereon is excellent in anti-corrosion property and paintadherence property and the product steel sheet is suitable for use as a can or container for drinks, etc.

United States Patent Asano et a1.

[4 1 July 15, 1975 STEEL SHEET HAVING A NICKEL COMPOSITE FILM AND A METHOD FOR MANUFACTURING THE SAME Inventors: Hidejiro Asano, Takami; Yashichi Ohyagi; Takatoshi Egawa, both of Kitakyushu, all of Japan Assignee: Nippon Steel Corporation, Tokyo,

Japan Filed: Sept. 10, 1973 Appl. No.: 395,841

Foreign Application Priority Data Sept. 19, 1972 Japan 47-93223 US. Cl. 29/1963; 29/470; 106/1;

29/1966; 427/229 Int. Cl B05d 3/10 Field of Search 117/71 M, 130 R, 160 R;

[5 6] References Cited UNITED STATES PATENTS 3,677,797 7/1972 Asano et a1. 117/71 M 3,715,231 2/1973 Ng et a1. 117/160 R 3,801,363 4/1974 Buck 117/160 R Primary Examiner-William E. Schulz Attorney, Agent, or FirmWatson, Leavenworth, Kelton & Taggart [57] ABSTRACT 14 Claims, No Drawings STEEL SHEET HAVING A NICKEL COMPOSITE FILM AND A METHOD FOR MANUFACTURING THE SAME BACKGROUND OF THE INVENTION As is well known. tin-free steel sheet of a Cr-plated type as well as tin-plated steel sheet have received much attention in recent years with the drastically increasing demands for containers for beer or other drinks.

However, the material tin becomes more expensive year after year and moreover the resources therefor tend to be drained. The tin-free steel sheet of the Crplated type has been developed for taking the place of the tin-plated steel sheet. It necessitates, however, electrolytic treatment for the manufacture thereof and thus requires expensive apparatus, labor and maintenance. Thus it cannot be said to be a decisive material as well.

In US. Pat. No. 3,677,797, it is disclosed that an aqueous solution is coated on the surface of a steel sheet. followed by a mere heat treatment, so that a film having an excellent anti-corrosive property may be formed; and that said aqueous solution is obtained by adding the nitrate or acetate of Cr, Mn, etc. to the nitrate or acetate of Ni or the mixture thereof. As compared with the conventional product of the same kind, the product obtained by the method disclosed in this US. patent shows that the anti-corrosive property is identical to, or better than, that of the conventional product. In addition, since the method of the US. patent only requires a simple heat treatment, it is quite advantageous with respect to the apparatus, labor, maintenance. etc. Moreover, it is very economical in view of public pollution since it does not produce any waste liquid.

The method of the US. patent exerts ideal effects in application to ordinary material or material to be subjected to a skin pass after annealing.

However, it has now been found that when the method of the US. patent is used under the condition that a greater part of the material to be used for carbonated beverage have recently become the 2 CR material or the material subjected to two cold rolling steps the film formed thereon is sometimes destroyed during the cold rollings, whereby it is difficult to expect as stable the maintenance of the anti-corrosive property of the material as that of the ordinary material.

It is therefore an object of the invention to provide a steel sheet and a method for manufacturing the same which overcome the above stated disadvantages encountered in the prior art.

It is another object of the invention to provide a method for the manufacture of a steel sheet having an extremely tough anti-corrosive film, which method is capable of being applied to 2 CR material as well as ordinary material with a mere heat treatment and yet preserves the advantages of low cost for apparatus, labor and maintenance and of the waste liquid.

SUMMARY OF THE INVENTION:

This invention relates to a steel sheet having a nickel composite film containing at least one member of the group consisting of Mo, W, Cu and K in the nickel film, and a method for manufacturing the same.

According to this invention there is provided a steel sheet having a nickel composite film containing at least one member selected from the group consisting of Mo, W, Cu and K in the nickel film. According to this invention, there is also provided a method for the manufacture of a steel sheet having a nickel composite film which comprises subjecting a surface of a steel sheet to a cleaning treatment, coating an aqueous solution on said cleaned surface, said aqueous solution being obtained by adding to an aqueous solution containing a metallic ion of Ni at least one member selected from the group consisting of an aqueous solution containing a metallic ion of Mo. an aqueous solution containing a metallic ion of W, an aqueous solution containing a metallic ion of Cu and an aqueous solution containing a metallic ion of K, heating the same in the atmosphere of a non-oxidizing gas, and thereby forming on said steel sheet a film consisting of Ni and at least one member selected from Mo, W, Cu and K.

One preferred embodiment of the method of the invention is described below.

One or more than one aqueous solutions containing metallic ions of Mo, W, Cu or K is added to an aqueous solution containing a metallic ion of Ni whereby a treating aqueous solution is obtained. This is coated on the surface of a steel sheet, which is then heated in the atmosphere of a non-oxidizing gas. A film composed of Ni and one member selected from the member consisting of Mo, W, Cu and K is then formed on the surface of the steel sheet. The temperature for heating is preferably between 200C and 750 C. The way of coating the treating aqueous solution may vary with the particular operation used, such as a spraying method, a rolling method or a dipping method, etc. If necessary, a surface active agent may be added. The film obtained on the surface of the steel sheet is considered to be a film consisting of two layers, the lower layer being Fe-Ni alloy and the upper layer being a mixed film of Ni with one or more selected from Mo, W, Cu and K. It has an excellent anti-corrosion property and lacquerability as shown in the example hereinafter described.

As set forth above, a steel sheet which is cheap, has an excellent anti-corrosion and lacquerability and is particularly adapted for use as a material for a can or container can be obtained according to this invention.

The amount adhering to the steel sheet from the treatment with aqueous solution may vary remarkably with the particular coating method used. The effective range is lg/l to lOOg/l, preferably 5g/l to 25g/l for the Ni ion, and 20g/l or less, preferably 5g/l or less for the Mo, W, Cu or K ion, respectively.

A specific example of the invention is described below.

EXAMPLE A steel sheet which has been subjected to the ordinary treatment or the cold rolling by means of a strip mill was electrolytically degreased and then coated by means of a dipping process with a treatment of aqueous solution which had been prepared by adding ammonium molybdate, ammonium tungstate, copper acetate, tri-potassium phosphate, or combination thereof, to an aqueous solution of nickel acetate. Immediately thereafter the coated steel sheet was heated to 650C in a furnace of bright annealing gas consisting of 7% H and the rest N whereby a nickel alloy film was formed. The coated steel sheet was then subjected to a skin pass by 1% and a rolling by 30% reduction, and then the rustprevention property, the resistance to the underfilm ((mmmrisnn of properties) Composition of the treating aqueous solution Resistance to corrosion underfilm After skin pass

After skin pass After 2 CR 1. Nickel acetate (ISg/l) plus ammonium molyhdate (fig/l) Nickel acetate (l5g/l) plus ammonium tungstate (Sg/l) 3. Nickel acetate (lSg/l) plus tri-potassium phosphate (Sg/l) 4. Nickel acetate (l5g/l) plus ammonium molybdate (3g/l) plus Copper ace tate (3g/l) 5. Nickel acetate (ZOg/l) 6. Nickel nitrate (ZOg/l) 2,0

plus chromium acetate (IOg/l) 7. Nickel nitrate (ZOg/l) plus aluminum nitrate (Sg/l) plus chromium acetate (5g/l) 8. Non-treated steel sheet Remarks The treating method: dipping; heating atmosphere H 7%.

N the rest; heating temperature 650C The number l to 4: this invention The number 5 to 8: the prior art The skin pass: 1% rolling The ZCR: rolling.

corrosion and the adhesion of lacquer were tested. The result is shown in Table 1.

1n the Table l, the figures shown are based upon the following definitions. l. The rust-prevention property It is indicated by the percentage area (0-100%) of the rust occurring within two months by a Pack Rust test (RH (Relativity humidity) 80%, C) which is a test simulating rust occurring before the use by the consumer. 2. The resistance to underfilm corrosion The steel sheet was coated with an epoxy resin lacquer, given a scratch of 0.1 mm width, and dipped in a solution of 1.5% NaCl plus 15% citric acid for 4 days. The degreeof the undertilm corrosion at the scratch portion was observed with the evaluation of 10 steps as follows.

10: Peel-off of the film is not observed at all.

9: Peel-off of 0.10 to 0.15 mm is observed. 8: Peel-off of 0.15 to 0.20 mm is observed. 7: Peel-off of 0.20 to 0.25 mm is observed. 6: Peel-off of 0.25 to 0.30 mm is observed. 5: Peel-off of 0.30 to 0.35 mm is observed. 4: Peel-off of 0.35 to 0.40 mm is observed. 3: Peel-off of 0.40 to 0.45 mm is observed. 2: Peel-off of 0.45 to 0.50 mm is observed.

1: Peel-off of 0.50 mm or more is observed.

3. The adhesion of lacquer After coated with lacquer, the steel sheet was sticked by a binder and the tensile strength was measured, whereby the maximum value was designated as 5 and the minimum value as 1 for the scale of the binding strength of the lacquer.

We claim:

1. A method for the manufacture of a steel sheet having a nickel composite film which comprises subjecting a surface of a steel sheet to a cleaning treatment. coating an aqueous solution on said cleaned surface, said aqueous solution being obtained by adding to an aqueous solution containing a metallic ion of nickel at least one member selected from the group consisting of an aqueous solution containing a metallic ion of molybdenum, an aqueous solution containing a metallic ion of tungsten, an aqueous solution containing a metallic ion of copper and an aqueous solution containing a metallic ion of potassium, heating the same in the atmosphere of a non-oxidizing gas, and thereby forming on said steel sheet a film consisting of nickel and at least one member selected from molybdenum, tungsten, copper and potassium.

2. A method according to claim 1 in which the heating is held at temperatures between 200C and 750C.

3. A method according to claim 1 in which the coating is held by means of spraying, rolling or dipping.

4. A method according to claim 1 in which a surface active agent is added in the coating.

. 5. A method according to claim 1 in which the amount adhering from the treatment with aqueous solution is lg/l to g/l for the nickel ion, and 20g/l or less for the molybdenum, tungsten, copper or potassium ion, respectively.

6. A steel sheet having a nickel composite film containing at least one member selected from the group consisting of molybdenum, tungsten, copper and potassium in the nickel film.

'7. A steel sheet having a nickel composite film consisting of two layers, the lower layer being iron-nickel alloy and the upper layer being a mixed film of nickel with one or more member selected from the group consisting of molybdenum, tungsten, copper and potassium.

8. A method according to claim 5 in which the amount adhering from the treatment with aqueous solution is 5g/l to 25g/l for the nickel ion and Sg/l or less for the molybdenum, tungsten, copper or potassium ion, respectively.

9. A method for the manufacture of a steel sheet having a nickel composite film which comprises subjecting a surface of a steel sheet to a cleaning treatment, coating an aqueous solution on said cleaned surface, said aqueous solution being obtained by adding to an aqueous solution of nickel acetate at least one member selected from the group consisting of an aqueous solution of ammonium molybdate, an aqueous solution of ammonium tungstate, an aqueous solution of copper acetate and an aqueous solution of tri-potassium phosphate, heating the same in the atmosphere of a nonoxidizing gas, and thereby forming on said steel sheet a film consisting of nickel and at least one member selected from molybdenum, tungsten, copper and potassium.

10. A method according to claim 9 in which the heating is held at temperatures between 200C and 750C.

11. A method according to claim 9 in which the coating is held by means of spraying, rolling or dipping.

12. A method according to claim 9 in which a surface active agent is added to the coating.

13. A method according to claim 9 in which the amount adhering from the treatment with aqueous solution is lg/l to l00g/I for the nickel ion and 20g/l or less for the molybdenum, tungsten, copper and potassium ion, respectively.

14. A method according to claim 13 in which the amount adhering from the treatment with aqueous solution is Sg/l to 25g/l for the nickel ion and Sg/l or less for the molybdenum, tungsten, copper or potassium ion, respectively. 

1. A METHOD FOR THE MANUFACTURE OF A STEEL SHEET HAVING A NICKEL COMPOSITE FILM WHICH COMPRISES SUBJECTING A SURFACE OF A STEEL SHEET TO A CLEANING TREATMENT, COATING AN AQUEOUS SOLUTION ON SAID CLEANED SURFACE, SAID AQUEOUS SOLUTION BEING OBTAINED BY ADDING TO AN AQUEOUS SOLUTION CONTAINING A METALLIC ION OF NICKEL AT LEAST ONE MEMBER SELECTED FROM THE GROUP CONSISTING OF AN AQUEOUS SOLUTION CONTAINING A METALLIC ION OF MOLYBDENUM, AN AQUEOUS SOLUTION CONTAINING A METALLIC ION OF TUNGSTEN, AN AQUEOUS SOLUTION CONTAINING A METALLIC ION OF COPPER AND AN AQUEOUS SOLUTION CONTAINING A METALLIC ION OF POTASSIUM, HEATING THE SAME IN THE ATMOSPHERE OF A NON-OXIDIZING GAS, AND THEREBY FORMING ON SAID STEEL SHEET A FILM CONSISTING OF NICKEL AND AT LEAST ONE MEMBER SELECTED FROM MOLYBDENUM, TUNGSTEN, COPPER AND POTASSIUM.
 2. A method according to claim 1 in which the heaTing is held at temperatures between 200*C and 750*C.
 3. A method according to claim 1 in which the coating is held by means of spraying, rolling or dipping.
 4. A method according to claim 1 in which a surface active agent is added in the coating.
 5. A method according to claim 1 in which the amount adhering from the treatment with aqueous solution is 1g/l to 100g/l for the nickel ion, and 20g/l or less for the molybdenum, tungsten, copper or potassium ion, respectively.
 6. A steel sheet having a nickel composite film containing at least one member selected from the group consisting of molybdenum, tungsten, copper and potassium in the nickel film.
 7. A steel sheet having a nickel composite film consisting of two layers, the lower layer being iron-nickel alloy and the upper layer being a mixed film of nickel with one or more member selected from the group consisting of molybdenum, tungsten, copper and potassium.
 8. A method according to claim 5 in which the amount adhering from the treatment with aqueous solution is 5g/l to 25g/l for the nickel ion and 5g/l or less for the molybdenum, tungsten, copper or potassium ion, respectively.
 9. A method for the manufacture of a steel sheet having a nickel composite film which comprises subjecting a surface of a steel sheet to a cleaning treatment, coating an aqueous solution on said cleaned surface, said aqueous solution being obtained by adding to an aqueous solution of nickel acetate at least one member selected from the group consisting of an aqueous solution of ammonium molybdate, an aqueous solution of ammonium tungstate, an aqueous solution of copper acetate and an aqueous solution of tri-potassium phosphate, heating the same in the atmosphere of a non-oxidizing gas, and thereby forming on said steel sheet a film consisting of nickel and at least one member selected from molybdenum, tungsten, copper and potassium.
 10. A method according to claim 9 in which the heating is held at temperatures between 200*C and 750*C.
 11. A method according to claim 9 in which the coating is held by means of spraying, rolling or dipping.
 12. A method according to claim 9 in which a surface active agent is added to the coating.
 13. A method according to claim 9 in which the amount adhering from the treatment with aqueous solution is 1g/l to 100g/l for the nickel ion and 20g/l or less for the molybdenum, tungsten, copper and potassium ion, respectively.
 14. A method according to claim 13 in which the amount adhering from the treatment with aqueous solution is 5g/l to 25g/l for the nickel ion and 5g/l or less for the molybdenum, tungsten, copper or potassium ion, respectively. 